The present disclosure relates in general to systems and methodologies for controlling the therapeutic application of neural stimulation. More specifically, the present disclosure relates to systems and methodologies for analyzing the results of muscle contractions or movements in order to develop parameters for controlling the therapeutic application of neural stimulation to treat neurological disorders.
Different types of therapeutic stimulation may be applied to neurological systems to treat variety of neurological disorders. For example, therapeutic neural stimulation may be applied to the brain to treat a variety of brain related disorders. One example of a therapeutic neural stimulation system is known generally as deep brain stimulation (DBS). DBS is a neurosurgical procedure involving the implantation of a medical device called a brain pacemaker, which sends electrical impulses, through implanted electrodes, to specific parts of the brain (brain nucleus) for the treatment of movement and affective disorders. DBS in select brain regions has provided therapeutic benefits for otherwise-treatment-resistant movement and affective disorders such as Parkinson's disease, essential tremor, dystonia, chronic pain, major depression and obsessive-compulsive disorder (OCD).
A contemporary DBS system includes three components, namely an implanted pulse generator (IPG), a lead and an extension. The IPG is a battery-powered neurostimulator encased in a titanium housing. The IPG sends electrical pulses to the brain to interfere with neural activity at the target site. The lead is a coiled wire insulated in polyurethane with four platinum iridium electrodes and is placed in one or two different nuclei of the brain. The lead is connected to the IPG by the extension, which is an insulated wire that runs below the skin and extends from the head down the side of the neck and behind the ear to the IPG. The IPG is placed subcutaneously below the clavicle or, in some cases, the abdomen. DBS leads are placed in the brain according to the type of symptoms to be addressed. For example, to treat non-Parkinsonian essential tremor, the lead is typically placed in the ventrointermediate nucleus of the thalamus.
Instruments for direct electrical brain stimulation are currently available from several companies (e.g., Medtronics, Neuromed, Cochlear Corp., Advanced Bionics). An important step in applying neural stimulation is determining the appropriate neural stimulation parameters in order to optimize efficacy of stimuli to be ultimately used in treatment. If the stimulation is electrical signals, the stimulation parameters may be frequency, pulse duration, duty cycle, etcetera. The effectiveness of a neural stimulation treatment can depend on the effectiveness of the criteria for choosing the stimulation parameters of a neural stimulation procedure.